Everyone should have to work as either bar staff, in retail or waiting tables for three months to sort out peoples shitty manners?
I work in a pub occasionally for some extra cash. I recently had a woman who I couldn’t serve as she had no ID kick off like fuck and tell me she was going to speak to the manager and I wasn’t going to have a job in the morning 
the landlord was there who turned around and said “firstly, no ID no service, secondly talk to my staff like that and you can also considered yourself barred.” Her face was a picture 
When I was at university about ten years ago I did a lot of waiting and had someone demand to speak to the manager because I carried three plates of food to them but needed to go back for the fourth (which would have taken me maybe 15 seconds) but she wanted it all right there NOW.
I think it would be wonderful making these people work in these jobs for a good while